Effects of Maintenance on Quality of Performance of Cryotherapy Devices for Treatment of Precancerous Cervical Lesions

J Low Genit Tract Dis. 2018 Jan;22(1):47-51. doi: 10.1097/LGT.0000000000000359.


Objective: The aim of the study was to evaluate the impact of maintenance on performance of cryosurgical equipment used in El Salvador primary health clinics.

Materials and methods: Nine gynecological cryotherapy devices used in El Salvador were bench tested against a new machine of the same make and model. The devices were run for five successive double-freeze cycles. The El Salvador machines then received maintenance by a specialized engineer and another double-freeze cycle was performed. Temperature at the device probe tip was recorded throughout each cycle and ballistic gelatin was used as the tissue analogue to measure freeze ball dimensions achieved by the devices. Outcome measures were mean lowest-sustained temperatures and freeze ball mean weight, depth, and diameter. Paired and unpaired t tests were used to compare results premaintenance versus postmaintenance and postmaintenance versus the reference, respectively.

Results: Premaintenance versus postmaintenance freeze ball dimensions were significantly different (mean differences in weight = 2.31 g, p = .01; depth = 2.29 mm, p = .03; diameter = 3.51 mm, p = .02). However, postmaintenance dimensions were not significantly different than those of the reference (weight = 7.44 g vs. 8.39 g, p = .07; depth = 10.71 vs. 11.24 mm, p = .1; diameter = 31.38 mm vs. 32.05 mm, p = .3). Postmaintenance, minimum, and lowest-sustained temperatures were within the recommended clinical range.

Conclusions: Specialized maintenance was necessary for heavily used cryotherapy devices to perform adequately, highlighting the challenges of gas-based cryotherapy in low- and middle-income countries.

MeSH terms

  • Cryotherapy / instrumentation*
  • Cryotherapy / methods*
  • El Salvador
  • Female
  • Humans
  • Maintenance
  • Precancerous Conditions / therapy*
  • Quality of Health Care
  • Uterine Cervical Diseases / therapy*